CVE-2025-71097

MEDIUM EPSS 1.8%
Published Jan 13, 20265mo ago · Modified Jun 17, 20262w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Jan 13, 2026 5mo ago
Last Modified Jun 17, 2026 2w ago

Description

In the Linux kernel, the following vulnerability has been resolved: ipv4: Fix reference count leak when using error routes with nexthop objects When a nexthop object is deleted, it is marked as dead and then fib_table_flush() is called to flush all the routes that are using the dead nexthop. The current logic in fib_table_flush() is to only flush error routes (e.g., blackhole) when it is called as part of network namespace dismantle (i.e., with flush_all=true). Therefore, error routes are not flushed when their nexthop object is deleted: # ip link add name dummy1 up type dummy # ip nexthop add id 1 dev dummy1 # ip route add 198.51.100.1/32 nhid 1 # ip route add blackhole 198.51.100.2/32 nhid 1 # ip nexthop del id 1 # ip route show blackhole 198.51.100.2 nhid 1 dev dummy1 As such, they keep holding a reference on the nexthop object which in turn holds a reference on the nexthop device, resulting in a reference count leak: # ip link del dev dummy1 [ 70.516258] unregister_netdevice: waiting for dummy1 to become free. Usage count = 2 Fix by flushing error routes when their nexthop is marked as dead. IPv6 does not suffer from this problem.

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
1.8% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Affected Products 15

VendorProductVersionRange
linuxlinux_kernel*≥5.3.1  –  <5.10.248
linuxlinux_kernel*≥5.11  –  <5.15.198
linuxlinux_kernel*≥5.16  –  <6.1.160
linuxlinux_kernel*≥6.2  –  <6.6.120
linuxlinux_kernel*≥6.7  –  <6.12.64
linuxlinux_kernel*≥6.13  –  <6.18.4
linuxlinux_kernel5.3any
linuxlinux_kernel6.19any
linuxlinux_kernel6.19any
linuxlinux_kernel6.19any
linuxlinux_kernel6.19any
linuxlinux_kernel6.19any
linuxlinux_kernel6.19any
linuxlinux_kernel6.19any
linuxlinux_kernel6.19any

References 7

  • git.kernel.org https://git.kernel.org/stable/c/30386e090c49e803c0616a7147e43409c32a2b0e
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/33ff5c207c873215e54e6176624ed57423cb7dea
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/5979338c83012110ccd45cae6517591770bfe536
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/5de7ad7e18356e39e8fbf7edd185a5faaf4f385a
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ac782f4e3bfcde145b8a7f8af31d9422d94d172a
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/e3fc381320d04e4a74311e576a86cac49a16fc43
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ee4183501ea556dca31f5ffd8690aa9fd25b609f
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/30386e090c49e803c0616a7147e43409c32a2b0e
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/33ff5c207c873215e54e6176624ed57423cb7dea
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/5979338c83012110ccd45cae6517591770bfe536
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/5de7ad7e18356e39e8fbf7edd185a5faaf4f385a
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ac782f4e3bfcde145b8a7f8af31d9422d94d172a
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/e3fc381320d04e4a74311e576a86cac49a16fc43
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ee4183501ea556dca31f5ffd8690aa9fd25b609f
    Patch